<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style>
        span{
            width: 100px;
            text-align: justify;
            float: left;
        }
        span:after{
            content:'.';
            width: 100%;
        }
        input{
            width: 100px;
        }
    </style>
</head>
<body>
<div class="demo">
    <span>昵称</span>：<input type="text" style = 'width: 100px'><br><br>
    <span>电子邮箱</span>：<input type="email" style = 'width: 100px;'>
</div>
</body>
</html>